If you are getting headaches caused by your husband's aftershave, then the place for it is not the bathroom cupboard, but the bin!
If he wears it at the gym or anywhere else where you do not accompany him, he will still smell of it when he comes home again, and you will still be getting headaches.
Ignoring the problem is no good either, as often an allergy to one thing escalates into allergic reactions to anything that has been made with whatever the thing causing your reaction is.
it is honestly not worth the risk, as developing an allergy is unfortunately so much easier than curing it!